U.S. patent number 4,221,982 [Application Number 05/929,657] was granted by the patent office on 1980-09-09 for liquid cooled rectified-alternating current generator.
This patent grant is currently assigned to General Motors Corporation. Invention is credited to Gene D. Bricker, Louis J. Raver.
United States Patent |
4,221,982 |
Raver , et al. |
September 9, 1980 |
Liquid cooled rectified-alternating current generator
Abstract
A liquid cooled rectified-alternating current generator for
supplying direct current to electrical loads such as the battery
and other electrical loads on a motor vehicle. The generator has a
generator compartment containing a stator winding and a rotor. A
rectifier compartment is provided at the end of the generator which
contains diode rectifiers supported by heat sinks and connected to
the stator winding of the generator. A liquid coolant medium, such
as engine lubricating oil, is circulated through the generator. The
coolant is supplied under pressure to the rectifier compartment,
thence to the generator compartment and from there coolant is
exhausted into a suitable oil sump. The passage means for supplying
coolant from the rectifier compartment to the generator compartment
comprises a laterally extending passage having an inlet located
adjacent the heat sinks for the rectifiers. The length and position
of the passage is such that in any rotative position of the
generator sufficient oil is maintained in the rectifier compartment
to contact at least one of the heat sinks for the rectifiers. Thus,
when the fluid pressure system is shut down the rectifier
compartment will retain a certain amount of coolant so that
subsequent operation of the generator will not cause destruction of
the rectifiers due to overheating.
Inventors: |
Raver; Louis J. (Anderson,
IN), Bricker; Gene D. (Wilkinson, IN) |
Assignee: |
General Motors Corporation
(Detroit, MI)
|
Family
ID: |
25458241 |
Appl.
No.: |
05/929,657 |
Filed: |
July 31, 1978 |
Current U.S.
Class: |
310/59;
257/E25.026; 310/54; 310/68D |
Current CPC
Class: |
H01L
25/115 (20130101); H02K 9/19 (20130101); H02K
11/046 (20130101); H01L 2924/0002 (20130101); H01L
2924/0002 (20130101); H01L 2924/00 (20130101) |
Current International
Class: |
H01L
25/10 (20060101); H02K 9/19 (20060101); H01L
25/11 (20060101); H02K 11/04 (20060101); H02K
009/00 () |
Field of
Search: |
;310/68R,87,68D,52,58,54,59,53,60,57,65,112,89,263,266 ;363/141
;357/82 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Skudy; R.
Attorney, Agent or Firm: Meland; C. R.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A liquid cooled rectified-alternating current generator
comprising, housing means defining a generator compartment, a
stator winding disposed within said generator compartment, means
including rotor means rotatable with respect to said stator winding
for causing an alternating current to be generated in said stator
winding when said rotor means is rotated, housing means defining a
rectifier compartment disposed adjacent said generator compartment
and separated therefrom by a laterally extending wall common to
said compartments, means defining an inlet passage adapted to be
connected to a source of pressurized liquid cooling medium for
supplying liquid cooling medium to said rectifier compartment,
first passage means extending through said laterally extending wall
for connecting said rectifier compartment and said generator
compartment, rectifier means disposed within said rectifier
compartment comprising at least one heat sink means supporting a
rectifier means, said rectifier means electrically connected to
said stator winding, said heat sink means being spaced from said
first passage means, means defining second laterally extending
passage means having an inlet located adjacent said heat sink means
connecting said inlet to said first passage means, the length of
said second passage means being such that liquid cooling medium in
said rectifier compartment is maintained at a level at which it
contacts at least a portion of said heat sink means when said
rectifier compartment is positioned such that the inlet of said
second passage means can operate as a drain for liquid cooling
medium contained in said rectifier compartment when said rectifier
compartment is not being fed with pressurized liquid cooling
medium, and means defining an outlet passage connected to said
generator compartment for exhausting cooling medium therefrom.
2. A liquid cooled rectified-alternating current generator
comprising, housing means defining a generator compartment, rotor
means and stator means located in said generator compartment for
causing an alternating current to be generated in said stator
means, housing means defining a rectifier compartment disposed
adjacent said generator compartment, means defining an inlet
passage adapted to be connected to a source of pressurized liquid
cooling medium for supplying liquid cooling medium to said
rectifier compartment, first passage means disposed adjacent one
side of said rectifier compartment connecting said rectifier and
generator compartments, a plurality of heat sinks each carrying at
least one diode disposed adjacent an opposite side of said
rectifier compartment, means connecting said diodes to said stator
means, second laterally extending passage means having an inlet
disposed adjacent said heat sinks and an outlet connected to said
first passage means, the length and position of said second passage
means being such that liquid cooling medium in said rectifier
compartment is maintained at a level at which it contacts at least
one of said heat sinks when said rectifier compartment is
positioned such that the inlet of said second passage means can
operate as a drain for liquid cooling medium contained in said
rectifier compartment when said rectifier compartment is not being
fed with pressurized liquid cooling medium, and means defining an
outlet passage connected to said generator compartment for
exhausting cooling medium therefrom.
3. A liquid cooled rectified alternating current generator
comprising, housing means defining a generator compartment, rotor
means and stator means located in said generator compartment for
causing an alternating current to be generated in said stator
means, housing means defining a rectifier compartment disposed
adjacent said generator compartment, an inlet passage connected to
said rectifier compartment, an outlet passage connected to said
generator compartment, said inlet and outlet passages being adapted
to be connected to a pressurized source of liquid cooling medium
for circulating cooling medium through said rectifier and generator
compartments, first passage means disposed adjacent one side of
said rectifier compartment connecting said rectifier and generator
compartments, a pair of heat sinks disposed adjacent an opposite
side of said rectifier compartment, diodes electrically connected
to said stator means supported by said heat sinks, and second
laterally extending passage means having an inlet disposed between
portions of said heat sinks and an outlet connected to said first
passage means, the length and position of said second passage means
being such that liquid cooling medium in said rectifier compartment
is maintained at a level at which it contacts at least one of said
heat sinks when said rectifier compartment is positioned such that
the inlet of said second passage means can operate as a drain for
liquid cooling medium contained in said rectifier compartment when
said rectifier compartment is not being fed with pressurized liquid
cooling medium.
4. A liquid cooled rectified alternating current generator
comprising, a frame having a laterally extending wall, said frame
having first and second portions extending axially in opposite
directions from said laterally extending wall, means including said
first frame portion defining a generator compartment, outlet
passage means connected to said generator compartment for
exhausting liquid cooling medium therefrom, rotor means and stator
means located in said generator compartment for causing an
alternating current to be generated in said stator means, end plate
means secured to an end of said second frame portion to define a
rectifier compartment therewith, means defining an inlet passage
adapted to be connected to a source of pressurized cooling medium
for supplying liquid cooling medium to said rectifier compartment,
first passage means extending through said laterally extending wall
and disposed adjacent one side of said rectifier compartment for
connecting said rectifier and generator compartments, a plurality
of heat sinks each carrying at least one diode located adjacent an
opposite side of said rectifier compartment, means connecting said
diodes to said stator means, second laterally extending passage
means having an inlet located adjacent said heat sinks and an
outlet connected to said first passage means, said second passage
means being formed by a pair of spaced ribs that are integral with
said laterally extending wall and said end plate means, the end
plate means serving to close the open end of a channel formed by
said spaced ribs, the length and position of said second passage
means being such that liquid cooling medium in said rectifier
compartment is maintained at a level at which it contacts at least
one of said heat sinks when said rectifier compartment is
positioned such that the inlet of said second passage means can
operate as a drain for liquid cooling medium contained in said
rectifier compartment when said rectifier compartment is not being
fed with pressurized cooling medium.
Description
This invention relates to liquid cooled dynamoelectric machines and
more particularly to an oil cooled diode-rectified alternating
current generator suitable for use as the battery charging
generator in a motor vehicle electrical system.
Diode-rectified alternating current generators can be of the air
cooled type in which a fan draws air through the generator or can
be arranged to be oil cooled in which case engine lubricating oil
is circulated through the generator. The advantage of oil cooling
is that the generator is completely sealed to obtain a machine that
is generally not affected by environmental effects such as salt
spray, dust, water and chaff in the case of certain farm machinery.
In addition, the air cooled generator is normally disposed close to
the engine so that the temperature of the generator is related to
ambient air temperature and engine temperature both of which vary.
With an oil cooled generator the temperature of the engine oil is
nearly constant, when the engine reaches operating temperature, so
that the generator is subjected to constant temperatures which are
more predictable than air cooled generators.
One type of oil cooled diode-rectified alternating current
generator, which has rectifier and generator compartments, is
disclosed in the U.S. Pat. No. to Bertsche, Jr. et al.,
3,078,409.
When an oil cooled generator of the hinge mounted type is mounted
in the engine compartment of a motor vehicle the optimum rotative
position of the generator may vary from vehicle to vehicle
depending on the best piping arrangement for feeding oil to and
exhausting oil from the generator and the best arrangement for
connecting the generator pulley to the drive pulley of the engine.
Thus, one engine installation will require that the generator be
positioned in a certain position while another installation may
require that the generator be rotated from that position in order
to be best accommodated in the vehicle installation. With oil
cooled generators, that have a rectifier compartment connected to
the generator compartment, the oil in the compartment that encloses
the rectifiers and the heat sinks for the rectifiers may be
completely drained therefrom if the generator is in such a position
that the passage connecting the rectifier compartment and the
generator compartment is lowermost in the installation when the
system is shutdown. If this results in oil being drained out of
contact with the heat sinks that support the diode rectifiers the
subsequent energization of the system will cause the rectifiers and
heat sinks to be rapidly elevated in temperature since they are now
out of contact with the cooling medium.
It accordingly is one of the objects of this invention to provide a
liquid cooled rectified alternating current generator wherein
liquid coolant located in the rectifier compartment that houses the
rectifiers, and their heat sinks, is maintained in contact with at
least a part of heat sinks for the rectifiers regardless of the
rotative position of the generator.
In carrying this object forward the generator rectifiers and their
heat sinks are located adjacent one end of the rectifier
compartment and passage means is provided connecting the rectifier
compartment to the generator compartment. This passage means has a
laterally extending portion having an inlet located adjacent the
rectifier heat sinks and an outlet located near the other end of
the rectifier compartment. With this arrangement the laterally
extending passage will always maintain a level of coolant within
the rectifier compartment which is sufficient to contact at least
some portions of the heat sinks for the diode rectifiers regardless
of the rotative position of the generator.
Another object of this invention is to provide a diode-rectified
oil cooled alternating current generator wherein the laterally
extending passage that connects the area adjacent the rectifiers
and their heat sinks to the inlet to the generator compartment is
comprised of a pair of ribs formed on the end frame of the
generator.
IN THE DRAWINGS
FIG. 1 is a side view of the generator made in accordance with this
invention;
FIG. 2 is an end view of the generator shown in FIG. 1;
FIG. 3 is an opposite end view of the generator shown in FIG.
1;
FIG. 4 is a view of an end of the generator with the end plate
broken away;
FIG. 5 is a sectional view of the generator taken along lines 5--5
of FIG. 4;
FIG. 6 is a schematic circuit diagram of the electrical system of
the generator of this invention; and
FIG. 7 is a schematic illustration of the oil cooling circuit
utilized for supplying cooling oil to the generator of this
invention.
Referring now to the drawings, the liquid cooled generator of this
invention comprises die cast aluminum frames 10 and 12. An end
plate 14 is secured to one end of the frame 10 and, as will be more
fully described hereinafter, provides a closure for a liquid tight
rectifier compartment that houses the diode rectifiers and their
heat sinks.
The frame 10 has a tubular housing portion 16 extending axially in
one direction from central wall 18 (FIG. 5) and another housing
portion 20 extending in an opposite direction therefrom. Frames 10
and 12 are secured together by bolts 22 which are threaded into
threaded openings formed in housing portion 16. An O-ring 24 is
fitted to frame 12 and engages the end of housing portion 16. The
housing portion 16 and frame 12 define a liquid tight generator
compartment 26.
The end plate 14 is fixed to the end of housing portion 20 by
fasteners 28 threaded into frame 10. A gasket 30 is compressed
between the end plate 14 and the end of housing 20 to form a liquid
tight rectifier compartment 32.
The generator has two inlet openings, one of which is selected
during installation of the generator on a vehicle engine to feed
liquid coolant, such as engine oil, to the interior of rectifier
compartment 32. One inlet opening is designated 34 in FIG. 4 and is
formed in boss 35. Opening 34 is pipe threaded to receive a plug or
to be connected to an inlet pipe. The threaded opening communicates
with an orifice or opening 36 having a diameter of approximately
1.70 to 1.80 millimeters. The opening 36 provides an orifice which
restricts the flow of inlet coolant and provides for coolant
velocity over the rectifier diodes and their heat sinks in a manner
to be more fully described.
The other oil inlet to the generator is formed in housing boss 38.
As will be further described one of the inlets is closed by a plug
and the other connected to an inlet pipe when the generator is
mounted to an engine.
The generator has four oil drain openings, three of which are
plugged during use and one of which is connected to a drain pipe.
One of these openings is designated as 40 in FIG. 1 and another as
42 in FIG. 5. The other two openings are formed in bosses 44 and 46
shown in FIG. 3. The openings all extend through housing portion 16
so as to form an oil outlet for generator compartment 26. One of
the plugs for plugging an opening is designated 48 and shown in
FIG. 1.
In addition to the two oil inlet openings and the four oil outlet
openings, the generator is provided with two vent openings one of
which is plugged and the other of which is connected to a vent line
or pipe that in turn is connected to some point on the engine that
is at atmospheric pressure or higher during use of the generator.
Both vent openings extend through housing 16. These vent openings
are shown in dotted lines in FIG. 3 and designated 50 and 52. A
plug 54 is shown in FIG. 1 closing the vent opening 52 and vent
opening 50 is also shown in dotted lines in FIG. 1.
The frame 10 is provided with a wall 56 which engages gasket 30.
The gasket 30 also engages end wall 58 to form a sealed voltage
regulator compartment 60. Liquid coolant is not supplied to the
compartment 60 since it is separated from rectifier compartment 32
by wall 56.
The alternating current generator is of the brushless type and
includes a stator core 62 supported by housing 16 and frame 12. The
core is formed of magnetic material which carries a three-phase
delta-connected stator winding 64. The rotor of the generator
comprises pole members 66 and 68 formed of magnetic material having
interleaved teeth which may be generally of the type disclosed in
the U.S. Pat. No. to Raver 3,863,127. The rotor further includes a
cylindrical core member 70 formed of magnetic material which is
rotatable with the shaft 72.
The alternating current generator has a fixed field winding 74. The
field winding is wound on a spool portion 76 of a field core 77
which is formed of magnetic material. The core portion 77 is
secured to the wall 18 of the frame 10 by screws 78 that are
threaded into core 77. As will be evident to those skilled in the
art, when shaft 72 is rotated the poles 66 and 68 and the core 70
are rotated therewith with the result that an alternating voltage
is induced in stator winding 64 having a magnitude which depends
upon rotor speed and the amount of direct current supplied to field
winding 74.
The rotor shaft 72 is supported for rotation in roller bearing 82
and ball bearing 84 respectively supported by frames 10 and 12. An
O-ring seal 86 and an oil seal 88 are provided for preventing loss
of coolant supplied to the bearing 84 from the generator
compartment 26.
The rectifier compartment 32 contains two heat sinks 90 and 92
formed, for example, of aluminum material each of which supports
three silicon diodes. The heat sink 90 supports the three diodes 94
which are press fitted into openings located in the heat sink. The
heat sink 92 likewise carries three diodes 96 which are press
fitted into the openings formed in the heat sink 92. The heat sinks
90 and 92, as shown schematically in FIG. 6, form the positive and
negative direct current output terminals of a three phase full wave
bridge rectifier network. Thus, the three conductor leads 98
connected with the three phase winding 64 pass through a grommet
100 located in an opening formed in a part of frame 10 that
separates the rectifier and generator compartments. The grommet is
formed of a resilient insulating material and provides a fluid
tight connection between the generator compartment and the
rectifier compartment. These three conductors 98 are respectively
connected to terminal studs 102, 104 and 106.
The terminal studs 102 and 104 are supported by heat sink 90 which
also supports the terminal stud 108. The heat sink 92 supports
terminal stud 106 and also supports terminal studs 110 and 112. All
of the terminal studs are electrically insulated from the
respective heat sinks and one of the terminal studs 108 is shown in
the sectional view of FIG. 5. As can be seen the terminal stud 108
is press fitted to the interior of an insulator 114 which supports
and electrically insulates the terminal stud 108 from the heat sink
90. The terminal stud 108 has a threaded end (not illustrated)
which receives nuts 116 for retaining apertured electrical
connector terminals thereon. The other terminal studs are supported
in the same manner as terminal stud 108, that is, they are
electrically insulated from their respective heat sinks and each
stud has a threaded portion adapted to receive the opening of a
connector terminal and nuts for holding the terminal to the
terminal studs.
It will be evident from the wiring shown in FIG. 4 that the
arrangement of terminal studs and diodes provides the three-phase
full wave bridge rectifier network shown in FIG. 6. Thus, terminal
studs 106, 110 and 112 are respectively connected by wires, one of
which is identified 113, to the cathodes of diodes 96. Further, the
terminal studs 102, 104 and 108 are respectively connected to the
anodes of diodes 94 and one of these conductors is identified by
reference numeral 120. A conductor 122 connects studs 106 and 108
and a conductor 124 connects stud 106 to a terminal 126 supported
by frame 10. The stud terminal 126 is insulated from the frame by
insulation 128 which provides a fluid tight support for stud
126.
The heat sink 90 is secured to the frame 10 by screws 130 and 132
that pass through openings in the heat sink. One of the screws 130
is shown in the sectional view of FIG. 5. This screw is threaded
into a boss 134 integral with frame 10. The heat sink and screw are
both electrically insulated from frame 10 by insulators 136 and
138.
The other screw 132 is threaded into an opening formed in the end
frame 10. This screw passes through a terminal connector 140
connected to conductor 142, passes through an opening in one end of
connector plate 144 and then through an opening in heat sink 90.
The connector plate 144 is electrically connected to a direct
voltage output terminal stud 146 which serves as the positive
direct current output terminal for the generator. The terminal stud
146 is electrically insulated from the frame of the generator and
is also provided with insulation 148 which serves to form a liquid
tight connection for the terminal stud 146. The screw 132,
connector plate 144 and heat sink 90 are all electrically insulated
from the frame 10 by suitable insulator washers and bushings which
have not been illustrated. The screw 132 passes through another
axially extending boss portion which has not been illustrated but,
which like boss portion 134, serves to space the heat sink 90 from
an internal wall 150 of the frame 10.
The heat sink 92 is secured to the frame 10 by screws 152 and 154,
the heads of which are illustrated in FIG. 4. These screws pass
through openings in the heat sink 92 and through suitable bosses
like boss 134 to space the heat sink 92 from the wall 150. The heat
sink 92 is therefore mounted so that it is in alignment with the
heat sink 90 as the heat sinks would be viewed in FIG. 5. The heat
sink 92 need not be electrically insulated from the frame 10 when a
negative ground system is utilized as is illustrated in FIG. 6.
The conductor 142 passes through a part 160 fitted to a slot formed
in wall 56 and this part serves to provide a support for other
conductors connected between the regulator compartment 60 and the
rectifier compartment 32. When the end plate 14 is secured to the
frame 10 a liquid tight connection is provided by part 160 so as to
prevent any leakage between the rectifier compartment and the
regulator compartment. The part 160 may be formed of a suitable
resilient insulating material.
The wall 18 of the frame 10 has a passage 170 that is aligned with
a passage 172 formed in an insert 174. The passage 172 is aligned
with a passage 176 formed in field core 77. The insert 174 is
tightly clamped between frame wall 18 and field core 77 when the
field core is secured to the frame. Thus, the passages 170, 172 ans
176 form, in effect, a single passage connecting an area or chamber
180 to point 182 located adjacent one end of field coil 74.
The area or chamber 180 is formed in part by wall 56 and a part of
two walls or ribs 184 and 186 that extend axially toward plate 14
from wall 18. The ribs 184 and 186 are formed when the frame 10 is
cast and are therefore integral with wall 18. When the end plate 14
and gasket 30 are secured to frame 10 the gasket engages the ends
of walls 56, 184 and 186 to form chamber 180 and a passage 188
having an inlet 190. The inlet 190 is formed at a point where walls
184 and 186 terminate. The passage 188 supplies cooling oil to
chamber 180 and therefore supplies the inlet side of passage
170.
It is important to note that the inlet 190 of the passage 186 is
located closely adjacent the inner ends of heat sinks 90 and 92 and
at a point that is below the top ends 90A and 92A of the heat sinks
90 and 92. The term "top end" as just referred to is used in
conjunction with the position of the generator shown in FIG. 4.
Thus, it is assumed that the generator is mounted on the engine in
FIG. 4 in such a position that the inlet 190 is lowermost.
If it is assumed now that the generator is mounted in the position
rotated 180.degree. from its position shown in FIG. 4 the inlet 190
of passage 188 will be reversed from its position shown in FIG. 4,
or in other words would be uppermost in regard to fluid level
contained in rectifier compartment 32. Assuming this position for
the generator it will be appreciated that during a shutdown
condition of the generator where engine oil is not being supplied
thereto, oil can drain by gravity through passages 188, 170, 172
and 176 into the generator compartment 26. The level of oil,
however, can never drop below the level of inlet 190 so that it
will be apparent that even during a shutdown condition of the
generator some oil will be retained in compartment 32 and in
contact with at least portions of one or both heat sinks 90 and 92
at the oil level maintained in the compartment 32 by the position
of the inlet 190 relative to the heat sinks.
The bearing 82 is lubricated by engine oil passing from rectifier
compartment 32 to generator compartment 26. The outer end of the
bearing 82 is closed by a plug 193. However, a groove 194 is
provided which bypasses the plug 193 and provides bleed lubrication
for bearing 82. The groove 194, as shown in FIGS. 4 and 5, is
formed in the frame 10. This groove is small and may have a depth
of approximately 2 millimeters and a width of about 2.5
millimeters. When the system is under pressure the groove 194
permits a small amount of oil to be fed through the bearing 82 from
rectifier compartment 32 to generator compartment 26. The opening
194 is so small that it has little or no drain effect on
compartment 32 when the system is shutdown.
The voltage regulator compartment 60 contains a transistor voltage
regulator generally designated by reference numeral 200. The
regulator is illustrated as a block in FIG. 6 and can take various
well known forms. The voltage regulator circuit, for example, may
be of the type disclosed in the above-mentioned Raver U.S. Pat. No.
3,863,127.
The generator field current is supplied by three diodes 202 in a
manner well known to those skilled in the art. The energization
circuit for the field 74 includes conductor 204, conductor 206,
conductor 208 and a control transistor (not illustrated) connected
between conductor 208 and ground. The voltage sensed by the voltage
regulator is supplied to the regulator via conductor 142 which is
connected to junction 146. The battery of the system is designated
by reference numeral 210 and is connected between direct voltage
output terminal 146 and ground. As is well known to those skilled
in the art the purpose of the regulator is to maintain a
predetermined regulated battery charging voltage between junction
146 and ground. The regulator can take various physical
constructions and has not been shown in any great detail. As one
example, the regulator 200 may include a circuit board 214 carrying
various components of the regulator and a metal plate 216 which may
carry the power output transistor of the regulator. The regulator
is mounted to the frame of the generator within compartment 60.
In utilizing the oil cooled generator of this invention the user
mounts the generator on the engine in such a position that is
convenient for connecting various oil lines and for driving the
generator by a suitable pulley driven belt. The generator is fitted
with a drive pulley which is placed on generator shaft portion 72A
and is held in place by nut 214 and washer 216 in a manner well
known to those skilled in the art. The generator is of the hinge
mounted type and the bushings 220 and 222 are utilized for this
purpose. The generator has another threaded bushing 224 for
receiving a bolt to secure the generator to an adjusting strap as
is known to those skilled in the art. Thus, a bolt passing through
bushings 220 and 222 provides the pivot for the generator and the
bolt that cooperates with bushing 224 secures the generator to an
adjusting strap in the desired rotative position.
The user selects one of the inlet openings of the generator, for
example inlet opening 34, which can be most conveniently connected
to the engine. The user further selects one of the outlet openings,
for example outlet opening 40, as the drain for the installation.
Further, the user selects one of the vent openings 50 or 52 to be
connected to a point of atmospheric pressure or higher in the
installation. The vent opening selected will be the uppermost vent
opening of the generator after the generator has been mounted in a
desired rotative position. The remainder of the inlet, outlet and
vent openings are all plugged by suitable plugs.
Referring now to FIG. 7, a schematic oil circulating diagram for
the generator of this invention is illustrated. It is seen that one
of the outlet openings of the generator is connected to a pipe 230
which leads to an oil sump 232 which may be, for example, the oil
sump of a diesel engine. One of the vent openings (uppermost in the
installation) is connected to a pipe 234 which in turn is connected
to a point of atmospheric pressure or higher on the engine which
has been designated by reference numeral 236.
Engine lubricating oil from the oil sump 232 is supplied to an
inlet of a pump 238 which supplies pipe 240. The pipe 240 is
intended to indicate the general oil circulating system of a diesel
engine and may include an oil filter and an oil cooler, neither of
which have been illustrated. After the oil has been cooled and
filtered it is supplied to the rectifier compartment 32. The oil is
then forced through the passage 170 connecting the rectifier and
generator compartments and some of the oil, as previously pointed
out, is used to lubricate the bearing 82 via the bleed opening 194.
The oil then exits via a drain opening where it is supplied to the
pipe 230.
The oil cooling circuit is a parallel circuit to that of the main
engine lubricating system and the oil supplied to the rectifier
compartment 32 may be taken off a diesel engine oil gallery which
is supplied with filtered and cooled oil.
When oil under pressure is supplied from pipe 240 to the rectifier
compartment 32 it passes through an orifice, for example the
orifice 36 (FIG. 4) and this orifice is aligned with the heat sink
90 such that a high velocity oil spray is applied to the heat sink
90. If the inlet opening in the boss 38 had been utilized as the
oil inlet the orifice provided for that inlet of the generator,
which has not been illustrated, would provide a high velocity flow
of inlet oil against the rectifier heat sink 92. Thus, the orifice
formed in boss 38 is aligned with the heat sink 92 in the same
manner as the alignment of the orifice 34 with heat sink 90.
The oil is supplied at high velocity to cool heat sinks 90 and 92
and the diodes carried thereby and then passes from the rectifier
compartment 32 to the generator compartment 36 via inlet opening
190 of passage 188, passage 188, chamber 180, passage 170, passage
172 and passage 176 to the outer periphery of field coil 74. The
outlet side of passage 176 (point 182) is disposed adjacent the
outer periphery of the field coil 74 so that coolant is forced
across the outer periphery of the coil from the outlet of passage
176. With the generator running the rotor rotates and oil is
circulated in contact with the stator winding 64 to cool this
winding. Some of the oil lubricates the bearing 84. The oil coolant
exits the generator via one of the outlet openings connected with
the pipe 230.
A small amount of oil passes between the rectifier compartment 32
and the generator compartment 20 via the small opening 194 and this
oil serves to lubricate the bearing 82.
The various inlet and oulet openings for the generator are provided
with pipe threads one of which has been identified by reference
numeral 34 (FIG. 4) and these are utilized to either accommodate a
plug when a particular oil inlet or outlet is not to be utilized or
to provide a means for connecting a pipe to the generator.
The venting of the generator compartment to atmosphere or higher
pressure prevents, by either vent opening 50 or 52, the forming of
a vacuum in the generator which would have the effect of impeding
drainage of cooling oil.
The length and position of passage 188 is such that at least some
oil will be retained in rectifier compartment 32 in contact with at
least a portion of one or both heat sinks 90 and 92 when the
generator is in any rotative position where inlet 190 can operate
as part of a drain.
During a shut down condition of the generator some coolant may
drain through passage 194 from rectifier compartment 32 to
generator compartment 26. This passage is positioned with respect
to the heat sinks 90 and 92 and ribs 184 and 186 such that at least
some coolant is retained in contact with a heat sink regardless of
rotative position of the generator. In this regard it is noted that
the ribs 184 and 186 form a wall or dam separating upper left and
right portions of rectifier compartment 32 when the generator is in
the FIG. 4 position. Thus, even if the generator were rotated
180.degree. from its FIG. 4 position, and assuming drainage through
passage 194, some coolant would still be retained in contact with
heat sink 92.
Further, the passage 36 connected to passage 34 and the
corresponding passages in boss 38 are located such that at least
some coolant is retained in contact with a heat sink in the event
of drainage through these passages during a shut down condition of
the generator.
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